Background & objective: Tracer is one of the important influencing factors for the successiveness of sentinel lymph node biopsy (SLNB) for breast cancer. This study was to evaluate the efficacy of methylene blue dye (MBD) as a tracer in SLNB for breast cancer, and to analyze its influencing factors.
Methods: From Mar. 2005 to Feb. 2006, 101 operable breast cancer patients with clinically negative axillary lymph node were enrolled. MBD was used alone as the tracer agent for SLNB. Axillary dissection was performed after SLNB. All sentinel lymph nodes (SLNs) were examined pathologically with HE staining.
Results: In this series, the identification rate of SLNs was 96.04% (97/101). The false negative rate was 11.76% (4/34). Excluding the patients received neoadjuvant chemotherapy, the false negative rate was 7.41% (2/27). The mean number of SLNs harvested was 2.05 in each patient. The size of SLNs was related to the pathologic results. Histological type, neoadjuvant chemotherapy, excisional biopsy had no impact on the identification rate of SLNs. The number of SLNs was correlated to the false negative rate of SLNB. The body mass index (BMI) was related to the identification rate of SLNs and the false negative rate of SLNB. No allergic reaction and skin necrosis had been observed.
Conclusions: MBD is a safety, reliable tracing agent for SLNB in breast cancer. Improved tracing technology is needed for the patients with higher BMI.